Messages in this thread | | | From | Ravi Bangoria <> | Subject | Re: [PATCH v4 0/5] Powerpc/Watchpoint: Few important fixes | Date | Mon, 14 Oct 2019 09:14:18 +0530 |
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On 10/12/19 1:01 PM, Christophe Leroy wrote: > > > Le 10/10/2019 à 08:25, Ravi Bangoria a écrit : >> >> >> On 10/10/19 10:14 AM, Ravi Bangoria wrote: >>> >>>>> @Christophe, Is patch5 works for you on 8xx? >>>>> >>>> >>>> Getting the following : >>>> >>>> root@vgoip:~# ./ptrace-hwbreak >>>> test: ptrace-hwbreak >>>> tags: git_version:v5.4-rc2-710-gf0082e173fe4-dirty >>>> PTRACE_SET_DEBUGREG, WO, len: 1: Ok >>>> PTRACE_SET_DEBUGREG, WO, len: 2: Ok >>>> PTRACE_SET_DEBUGREG, WO, len: 4: Ok >>>> PTRACE_SET_DEBUGREG, WO, len: 8: Ok >>>> PTRACE_SET_DEBUGREG, RO, len: 1: Ok >>>> PTRACE_SET_DEBUGREG, RO, len: 2: Ok >>>> PTRACE_SET_DEBUGREG, RO, len: 4: Ok >>>> PTRACE_SET_DEBUGREG, RO, len: 8: Ok >>>> PTRACE_SET_DEBUGREG, RW, len: 1: Ok >>>> PTRACE_SET_DEBUGREG, RW, len: 2: Ok >>>> PTRACE_SET_DEBUGREG, RW, len: 4: Ok >>>> PTRACE_SET_DEBUGREG, RW, len: 8: Ok >>>> PPC_PTRACE_SETHWDEBUG, MODE_EXACT, WO, len: 1: Ok >>>> PPC_PTRACE_SETHWDEBUG, MODE_EXACT, RO, len: 1: Ok >>>> PPC_PTRACE_SETHWDEBUG, MODE_EXACT, RW, len: 1: Ok >>>> PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW ALIGNED, WO, len: 6: Ok >>>> PPC_PTRACE_SETHWDEBUG, MODE_RANGE, DW ALIGNED, RO, len: 6: Fail >>>> failure: ptrace-hwbreak >>>> >>> >>> Thanks Christophe. I don't have any 8xx box. I checked qemu and it seems >>> qemu emulation for 8xx is not yet supported. So I can't debug this. Can >>> you please check why it's failing? >> >> PPC_PTRACE_SETHWDEBUG internally uses DAWR register and probably 8xx does >> not emulate DAWR logic, it only uses DABR to emulate double-word watchpoint. >> In that case, all testcases that uses PPC_PTRACE_SETHWDEBUG should be >> disabled for 8xx. I'll change [PATCH 5] accordingly and resend. > > I think the MODE_EXACT ones are OK with the 8xx at the time being.
Ok. I'll disable other tests for 8xx.
Also, I was bit wrong in above point. Actually, PPC_PTRACE_SETHWDEBUG with RANGE breakpoint also support DABR but the length will be 8 only. So I've to change my patch 1 also a bit (ptrace stuff). I'll resend the series with these changes.
> >> >> Also, do you think I should fix hw_breakpoint_validate_len() from [PARCH 1] >> for 8xx? I re-checked you recent patch* to allow any address range size for >> 8xx. With that patch, hw_breakpoint_validate_len() won't get called at all >> for 8xx. > > At the time being, the 8xx emulates DABR so it has the same limitations as BOOK3S. > My patch needs to be rebased on top of your series and I think it needs some modifications, as it seems it doesn't properly handle size 1 and size 2 breakpoints at least. > So I think that you should leave your Patch1 as is, and I'll modify the validate_len() logic while rebasing my patch.
Sure. Thanks for helping!
Ravi
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